Take a good look at them, judge their size and check how well they’ve been processed, as well as any content of undesirable elements (woody matter, stalks). The freshness of the leaves is revealed in their colour - pale leaves tend to be old.
Check the degree of natural aroma and pay attention to its intensity. The aroma hints at the tea’s origin, e.g. teas from Darjeeling have a hint of dried straw about them, while Assam smells a little of caramel.
This stage should reveal the colour typical for the area of the tea’s origin, as well as the processing and fermentation of the leaves. Tea from Assam is dark brown to black in shade, whereas Darjeeling is light to dark gold, and Sri Lanka is reddish gold. Fermented teas are darker than semi-fermented or non-fermented ones.
Steeping the tea leaves gives a real sense of the character of the tea. It is possible to recognise the quality of the harvest and its subsequent processing (look for undamaged leaves), and whether the tea’s pure or a blend. The scent highlights the intensity of the aroma and degree of fineness of the tea.
The aroma of a good tea should be typical of its origin, i.e. strong and multi-faceted. Taking Darjeeling as an example, it should be fresh, fine, intensively flowery and muscatel.
Roll the tea around your tongue for a few seconds. Gauge the strength or richness of flavour of the tea, as well as the degree to which the inherent tannins were infused (any bitterness present).
The longer the taste and aroma lasts, the better, during which it’s possible to get a feel for the purity of the tea; anything undesirable (an admixture) is shown through nuances atypical for tea.